The present invention generally relates to a carbon based environmental sensor, and more particularly to a carbon based digital sensor fabricated on silicon.
Sensing of chemical and biological elements in the environment is important for environmental monitoring and security concerns. It is desirable to have sensors with high sensitivity to such elements, and also to transmit the sensed information remotely, by wired or wireless means, to a distant monitoring point.
Graphene, which is a two-dimensional crystal of carbon atoms, can be used for gas and chemical sensing or biosensing. Carbon nanotubes are a rolled up crystals of carbon, with a crystal structure the same as graphene. Due to their large surface-to-volume ratio and electronic sensitivity to surface molecules, graphene and carbon nanotubes can be used for sensing an analyte, such as an environment gas or chemical. The electronic sensitivity of graphene and carbon nanotubes can be manifested as a change in their resistance when molecules are absorbed from the environment. Graphene can be treated, functionalized, or carbon engineered to detect specific molecules or analytes. Graphene and carbon nanotubes can be used for sensing analytes and to provide a digital signal. An analyte can also be referred to as a reactant.